JP2686289B2 - How to repair the color filter - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for repairing a color filter in which a dyeable resin is colored with a coloring material, and is used, for example, when performing color display on a liquid crystal display device. The present invention relates to a method suitable for repairing a color filter.

(Prior Art) A liquid crystal display device has a gap of about 1 to 10 μm provided between two transparent substrates such as a glass substrate having a transparent electrode, and liquid crystal is sealed between them to apply a voltage between the electrodes. The liquid crystal is driven to display.

Then, in order to perform color display, it is general to provide color filters of a plurality of colors on any transparent substrate between the gaps.

In the liquid crystal display device as described above, when the transparent electrode is formed on the color filter, a foreign matter of several μm to several tens of μm may adhere or be included in the color filter film. In particular, when a large color filter is manufactured, foreign substances are more likely to adhere than when a small color filter is manufactured.

Then, the presence of this foreign substance may cause a short circuit between the two electrodes via the liquid crystal layer, which may reduce the display area.

On the other hand, as a practical matter, even if the color filter is manufactured in an environment such as a clean room where the amount of generated dust is small, it is difficult to completely avoid adhesion of foreign matter and inclusion.

Therefore, a method of irradiating a laser beam to remove these foreign matters has been conventionally known.

(Problems to be Solved by the Invention) There are various kinds of foreign substances attached to or contained in the color filter film, such as metal pieces, dust particles from the human body,
The photosensitive resin etc. can be raised.

However, with ordinary laser light, the foreign matter that can be removed by irradiating a laser light of a specific wavelength is limited to a specific foreign matter, and only the laser light is transmitted to other types of foreign matter, and There is a problem that it cannot be removed.

Further, even when a laser beam of a specific wavelength is irradiated, the transmittance (or absorptivity) for the laser beam varies depending on the color of the colored layer of the color filter and the material of the protective film.
There is also a problem that it is difficult to set the laser light output.

Further, even when the color filter is removed by irradiation with laser light, the removed colored layer around the periphery is exposed, so that when the transparent electrode is formed or the alignment film is formed in the subsequent step,
Further, when the panel is assembled with the liquid crystal layer, the colored layer in the exposed portion is deteriorated, and the image quality of the liquid crystal display is deteriorated.

(Means for Solving the Problems) As a result of various studies to solve the above problems, the present inventor has
In a method of repairing a color filter in which a dyeable resin is colored with a coloring material, the fourth harmonic of the Nd: YAG laser light of the ultraviolet laser light (wavelength of 266 μm )
By irradiating with, the foreign substances were removed together with the color filter constituent substances in the vicinity of the foreign substances.

In addition, after the projections on the surface of the color filter are removed by laser light, the protective film is recoated.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a color filter (A) formed by a dyeing method or a pigment dispersion method.

On the upper surface of the colored pattern (2) formed on the upper surface of the transparent substrate (1), an acrylic resin layer (3) which is a protective layer for the colored pattern (2) is formed.

The coloring pattern (2) has various colors such as red, green and blue, and the material thereof is a natural resin such as gelatin, casein or glue which has excellent dyeability as a dyeable resin, and polyvinyl Synthetic resins such as alcohol, stilbazolium, polyimide, acrylic acid resin and the like can be used. Examples of colorants include dyes and pigments.

Then, as a means for producing such a color filter (A), for example, a printing method or a photolithography technique can be cited.

Reference numeral (4) shows a foreign substance attached to the colored pattern (2) and enclosed in the acrylic resin layer (3). The foreign substance (4) causes protrusions (5) on the surface of the color filter (A).
Are formed.

In the case of the above, depending on the substance of the coloring pattern (2), the light absorption rate in the visible or infrared region is significantly different depending on the wavelength, and the specific long wavelength laser (400 μm
With a laser beam of m or more), depending on the location in the color filter (A), even if the laser beam is irradiated, there is a foreign substance (4).
There is a problem that it cannot be removed.

Therefore, in the present invention, the fourth harmonic (wavelength of 266 μm) of Nd: YAG laser light, which is a laser light in the ultraviolet region and has a high light absorptance with respect to the color filter (A), is projected on the surface of the color filter (A). The foreign matter (4) is removed together with the color filter constituent substances around the foreign matter (4) by irradiating the same with (5).

Fig. 2 shows the projection (5) with the fourth harmonic (wavelength 266μm) of Nd: YAG laser light (wavelength 1060μm) excited by a CW (continuous wave) excitation Q switch, passed through a hole slit of 20 × 20μm, and 780V The number of shots is 5, and the foreign matter (4) and the color filter constituent substances around it are removed by irradiation.

Further, when the protrusions (5) are removed, the color filter colored layer portion (2) around the protrusions (5) is exposed. Therefore, in this state, the transparent conductive film and the alignment film are formed, and the liquid crystal layer is formed. When a process such as panel assembly is performed, a solvent used in a later step may enter from the exposed portion to discolor the colored layer portion (2).

Therefore, after removing the projections (5) on the surface of the color filter (A) with laser light, the protective film is recoated on the surface of the color filter (A).

FIG. 3 shows a state in which an acrylic resin protective film (6) is applied to the exposed color filter colored layer portion (2) after the protrusions (5) are removed.

FIG. 4 shows that the transparent conductive film (7) is further laminated on the protective film (6) by a sputtering device.

When a liquid crystal display device was prepared by enclosing liquid crystal using the color filter restored as described above, a good display device without short circuit between upper and lower electrodes could be obtained.

(Effect of the Invention) According to the present invention, it is possible to collectively remove the protrusions on the surface of the color filter regardless of the type of foreign matter and the material of the color filter, so that a high-quality display device without a short circuit is manufactured. be able to.

Therefore, it is possible to remarkably improve the non-defective rate of the large-sized color filter, which is more likely to generate protrusions than the small-sized color filter.

Further, even if the transmissivity or the absorptivity to the laser light is different due to the difference in the material of the color filter, the output setting of the laser light can be easily performed.

Then, by re-applying the protective film and embedding the exposed portion of the color filter, the solvent and the like do not enter the colored portion even in the subsequent step, and the reliability of the product can be further improved.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a color filter, FIG. 2 is a sectional view of a color filter after projections are removed, and FIG. 3 is a sectional view of a color filter after applying a protective film. FIG. 4 is a cross-sectional view of the color filter after the transparent conductive films are laminated. A ... Color filter 1 ... Transparent substrate 2 ... Coloring pattern 3 ... Acrylic resin layer 4 ... Foreign matter 5 ... Protrusion 6 ... Protective film 7 ... Transparent conductive film

Claims (4)

(57) [Claims] 1. A method for repairing a color filter in which a dyeable resin is colored with a coloring material, wherein projections on the surface of the color filter due to foreign matter attached to or contained in the color filter are irradiated with the fourth harmonic of Nd: YAG laser light. Then, the foreign matter is removed together with the color filter constituent substance in the vicinity of the foreign matter. 2. The method of repairing a color filter according to claim 1, further comprising reapplying a protective film after removing the projections on the surface of the color filter with the laser beam. 3. The coloring material according to claim 1, which is a dye.
The method for repairing the color filter described in the item. 4. The color material according to claim 1, which is a pigment.
The method for repairing the color filter described in the item.